• Journal of Aerospace System Engineering
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• v.10 no.4
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• pp.75-83
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• 2016

This paper presents a survey of patents and an analysis of a conceptual study for the development of rotor drive systems in combined unmanned rotorcraft in. The patents were classified into 10 cases with respect to the rotor drive system development, and these are reviewed and analyzed in detail. The results describe development concepts for rotor drive systems for vehicles obtained through the patent analysis.

• 한국항공운항학회:학술대회논문집
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• 2016.05a
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• pp.9-13
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• 2016

Reaction drive rotor system is capable of providing hover and low speed capabilities to different aircraft concepts such as stopped rotor wing, canard rotor wing, compound gyroplane etc. Existing sizing and analysis tools for shaft drive rotor system cannot be applied directly to this system. The available methodologies to size this system were reviewed. Power available calculation procedure and factors affects it were addressed prior to sizing process. Various design issues of this system due to interrelationship of internal gas flow dynamics and rotor external aerodynamics was discussed. Finally, a modification that is required in existing sizing methodologies was identified and combined approach in sizing process to consider the interrelationship among engine, rotor and blade duct was introduced.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.2
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• pp.189-195
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• 2005

This paper presents a new velocity estimation strategy for a non-salient permanent magnet synchronous motor drive without high frequency signal injection or special PWM pattern. This approach is based on the d-axis current regulator output voltage of the drive system, which contains the rotor position error information. The rotor velocity can be estimated through a rotor position tracking PI controller that controls the position error at zero. For zero and low speed operation, the PI gain of the rotor position tracking controller has a variable structure according to the estimated rotor velocity. Then, at zero speed, the rotor position and velocity have sluggish dynamics because the varying gains are very low in this region. In order to boost the bandwidth of the PI controller during zero speed, the loop recovery technique is applied to the control system. The PI tuning formulas are also derived by analyzing this control system by frequency domain specifications such as phase margin and bandwidth assignment.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.49-60
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• 2008

In this technical paper, summarization of developmental results for the tilt-rotor SUAV Drive System being developed in the Smart UAV Development Center is carried out in view of design and analysis for the major components. The Drive System driving for the Rotor System of the SUAV is composed of very precise and advanced equipments, and also the applied technologies for development of the system had not ever experienced in the Korea. Therefore the collaboration study with an advanced company (EATI) in the USA performed in order to develop the SUAV Drive System.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.201-205
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• 2004

A method for driving and position sensing of TSRM(Toroidal Switched Reluctance Motor) using the search coil is presented in this paper. Position information of the rotor is essential for SRM drives. The rotor position sensor such as an opto-interrupter or high performance encoder is generally used for the estimation of rotor position. However, these discrete position sensors not only add complexity and cost to the system but also tend to reduce the reliability of the drive system. In order to solve these problems, in the proposed method, rotor position detection is achieved using the voltage waveforms induced by the time varying flux linkage in the search coils, and then the appropriate phases are excited to drive the SRM. But the search coil EMF is generated only when the motor rotates. Therefore the rotor position sensing method at standstill is also suggested.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.752-753
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• 2006

Oil Pump rotor is essential parts for automobile and, it is consisted of drive rotor and driven rotor in general. These parts are requested different properties according to environment. There are 2 types of Oil Pump rotor according to its usage. One is used for electric system, and the other is used for shaft-driven system. Especially, high precision and functionality is required in electric pump, and cost reduction is required in shaft-drive pump without slowing down its performance. This paper is mainly describing about the non-machine treated shaft-drive pump, based on the trial sample producing process.

• Journal of Industrial Technology
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• v.34
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• pp.15-20
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• 2014

Recently, PMSMs(Permanent Magnet Synchronous Motors) have become increasingly popular in various high-performance motor drive applications. However, the high-performance drive of PMSMs needs a position sensor such as a resolver, which increases not only the price of the system but also reduces the system reliability. This paper is on the implementation of sensorless control of a SPMSM, which drives a fan for cooling in appliances. In this paper, the rotor position for high-performance drive of a SPMSM is derived from back electromotive force (EMF) information proportional to the rotor speed. Also, the initial rotor position information for start-up is estimated from a saturation phenomenon of inductance. The validity of the proposed sensorless drives was confirmed by the experiment on the SPMSM drive systems for cooling fans of refrigerators and laptop computers.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.79-82
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• 2004

The rotor drive system in rotor-craft carries out power transmission from powerplant to rotors and the drive shafts are fallen into misaligned condition by the vibration of engine and shafts and the deformation of supporting structures. The high performance flexible coupling accommodates these misalignments of drive shafts. In this study, we compare the performance of the metalic flexible coupling with the composite flexible coupling through analytic method to develop the high performance flexible coupling used in the rotor drive system of UAV tilt-rotor.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.15-23
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• 2008

This paper describes the structural analysis results of KARI General Small-scaled Rotor Test System (GSRTS) operated in KARI to verify operational safety. This GSRTS was developed to conduct a froude and mach small-scaled rotor test. This analysis was performed to investigate the structural Factor of Safety for the various small-scale rotor system like articulated or hingeless rotor and to check the operational capability using given operational design load. Specially, drive system has several bearings, mechanical gears, shaft, etc. and these parts must be required to achieve an operational safety. The calculation was done by using geometric data and material properties by analytical method. This rotor test system should be operated within these calculated Factor of Safety. Furthermore, the operational limitation should be defined as applied to small-scale rotor system of KUH in future.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.11
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• pp.664-670
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• 2004

This paper presents a new velocity estimation strategy of a non-salient permanent magnet synchronous motor (PMSM) drive without high frequency signal injection or special PWM pattern. This approach is based on the d-axis current regulator output voltage of the drive system that has the information of rotor position error. The rotor velocity can be estimated through a rotor position tracking PI controller that controls the position error to zero. For zero and low speed operation, PI controller gains of rotor position tracking controller have a variable structure according to the estimated rotor velocity. In order to boost the bandwidth of PI controller around zero speed, a loop recovery technique is applied to the control system. The proposed method only requires the flux linkage of permanent magnet and is insensitive to the parameter estimation error and variation. The designers can easily determine the possible operating range with a desired bandwidth and perform the vector control even at low speeds. The experimental results show the satisfactory operation of the proposed sensorless algorithm under rated load conditions.